The present invention relates to a cylinder head, in a unit construction, for several cylinders of a water-cooled internal combustion engine having indirect or direct injection; the cylinder head has at least two gas-changing channels per cylinder which are arranged on that side opposite to the turbulence chambers or injection nozzles.
Cylinder heads of the foregoing type are used for example with the "Rabbit" or "Golf"Diesel of Volkswagen. A problem of the presently employed cylinder heads, however, is the high thermal stressing in the region between the valves, i.e. the valve stems, and in the region of the turbulence chambers or injection nozzles, which high thermal stressing can lead to the formation of cracks at the mentioned locations. A further disadvantage with the conventional cylinder heads of this type of construction is a weakening of the cylinder-head-delimiting wall above the cylinder head gasket on one side due to placement of the intake and exhaust channels on this one cylinder head side. Furthermore, it is disadvantageous that the conventional cylinder heads have available only at most two oil-return channels, which are generally arranged on the two end faces of the cylinder head, as a result of which the oil removal and the oil exchange in the central region is unfavorably affected, which can lead to problems with valve stem seals on cylinder heads having overhead camshafts.
It is an object of the present invention to provide a water-cooled cylinder head of the foregoing general type which does not have the aforementioned disadvantages and which is suitable for mass production due to good casting capability. Additionally, the forces introduced to the cylinder head screws or bolts are to be better concentrated at the combustion chamber walls. The resilience or yield capability with a cylinder head having unit construction is to be increased for better adaptation to the cylinder block according to a further object of the present invention.